Wide area and large capacity intelligent object tracking system and method

ABSTRACT

The wide area object and large capacity tracking system comprises a plurality of tags to be attached to an object to be tracked and being configured so as to generate and transmit a tag signal indicative of the object-related information, a tag-recording unit configured to program a tag&#39;s memory with object-related information pertaining to the object to which the tag is attached, a central server including a memory for storing the information stored to the tags; primary base stations, each being coupled to the central server and being coupled to a pair of secondary base stations so as to define a tag detecting cell; each of the primary and secondary base stations being configured to receive tag signals, each yielding three received signals indicative of the location of a tag within the cell; and at least one portable control unit wirelessly coupled to the system and being configured to receive tag signals and object-related information. The system allows determining both in which cell each tag is located and its precise location in the cell.

FIELD OF THE INVENTION

The present invention relates to object tracking systems. Morespecifically, the present invention is concerned with wide area objectand large capacity tracking system and method.

BACKGROUND OF THE INVENTION

Each year, hundred of thousands of baggagebaggages are lost in airportsthroughout the world. These losts cause tens of millions of dollarsworth to the airlines in reimbursements, searching fees, storing, andrerouting.

There exists an international database for lost baggages: the SITAdatabase, which is shared by about half the airlines. However, thisdatabase only contributes to retracing already lost baggages and doesnot prevent their losts.

The well-known Sep. 11, 2001 events have shown the tremendous need forincreasing security in airport regarding people movement in specificzone.

The increasing competition among airlines, the difficulty for airlinesto keep their market share, in addition to the fact that their clientsare more demanding than ever result in the introduction of new systemsfor tracking baggages.

For example, Watanabe et al. in the U.S. Pat. No. 5,478,991, issued onDec. 26, 1995 and entitled “Aircraft Baggage Managing System Utilizing AResponse Circuit Provided On A Baggage Tag” describe an example of suchsystems. Watanabe et al. teach a wireless baggage tracking systemincluding electronic tags configured so as to transmit a radio signal, areader disposed at a classification point of the baggage to transmit aquestion electromagnetic wave to the tag and to receive a responsethereto, and a computer for inputting and storing baggage informationread on the tags.

A first drawback of Watanabe's system is that it only allows detectingbaggage at specific places along a baggage belt conveyor and not at anyplace in the airport. Moreover, a relatively long delay may occurbetween the time a baggage is actually lost and the moment the systemdetects the lost. Another drawback is that Watanabe's system does notallow any means to retrace a lost baggage. A further drawback is that itdoes not provide any means to manage the tags.

The U.S. Pat. No. 6,333,690, issued to Nelson et al. on Dec. 25, 2001and entitled “Wide Area Multipurpose Tracking System” describes a systemfor electronically tracking and locating objects. The system includes atag for sending a coded signal to a network of receiver base stationswith limited but overlapping reception ranges. Each receiver basestation places in its own memory the time at which a record enters itsrange, remains in range, and the time at which it leaves.

Nelson's system shares common drawbacks with Watanabe's such as the factthat it does not allow a precision beyond the range of the receiver,yielding a relatively long delay between the time a baggage is actuallylost and the moment the system detects the lost. It does not allow anymeans to retrace a lost baggage, and it does not provide any means tomanage the tags.

An improved wide area object and large capacity tracking system istherefore desired.

OBJECTS OF THE INVENTION

An object of the present invention is therefore to provide improved widearea object and large capacity tracking system and method.

SUMMARY OF THE INVENTION

More specifically, in accordance with a first aspect of the presentinvention, there is provided a wide area object tracking systemcomprising:

at least one primary base station and a pair of secondary base stations;each of the pair of secondary base stations being so coupled to theprimary base station so as to define a tag detecting cell; each of theprimary and two secondary base stations being configured to receive atag signal broadcast from a tag attached to an object to be tracked,yielding three received signals indicative of the location of the tagwithin the cell;

whereby a plurality of overlapping the tag detecting cells in a givenspace would allow tracking objects at any place within the given space.

More specifically, a specific embodiment of a wide area object trackingsystem in accordance with the first aspect of the present inventionfurther comprises:

at least one tag; each of the at least one tag being to be attached toan object to be tracked; the at least one tag including a memory toreceive object-related information pertaining to the object to betracked and being configured so as to generate and transmit a tag signalindicative of the object-related information;

a central server including a memory for storing the object-relatedinformation;

a tag recording unit coupled to the central server and being configuredto program the memory of the at least one tag with the object-relatedinformation; and

at least one portable control unit wirelessly coupled to at least one ofthe central server and the at least one primary base station; the atleast one portable control unit being configured to receive at least oneof the tag signal, the object-related information and the location ofthe tag within the detecting cell.

A wide area object and large capacity tracking system according to thepresent invention allows, for example, managing efficiently an objectinventory. It can also be used to track baggages in and throughoutairports.

Indeed, a wide area baggage tracking system according to the presentinvention allows airlines to manage baggages and other objects orpersons, allowing to minimize their losts and offering an efficient wayto retrace lost baggages and improve baggage management efficiency.

A wide area and large capacity intelligent baggage tracking systemaccording to the present invention allows:

-   -   tracking baggages at any points between the baggage registering        desk at the departure airport to the baggage recuperating        carrousel at the arrival airport;    -   providing to passengers means to consult information on the        location of its baggage; and    -   establishing the precise trajectory of baggages, of other        objects, and people in the airport, and allowing the airport's        security and managing people tracking information; and    -   managing tags during and between activations.

In accordance to a second aspect of the present invention, there isprovided a wide area object tracking method comprising:

activating at least one tag to be attached to an object to be trackedcausing the at least one tag to broadcasting a tag signal indicative ofinformation pertaining to the object to be tracked;

providing at least one primary base station and a pair of secondary basestations; the pair of secondary base stations being so coupled so as todefine a tag detecting cell with the primary base stations;

each of the at least one primary base station and the pair of secondarybase stations coupled thereof listening for tag signals within the tagdetecting cell; and

upon detection of one of the tag signals by the at least one primarybase stations and the pair of secondary base stations coupled thereof,yielding three respective received signals, using the three respectivereceived signals to determine the location of the at least one tagwithin the tag detecting cell.

Finally in accordance to a third aspect of the present invention, thereis provided a wide area intelligent object tracking system comprising:

a plurality of tags, each to be attached to a different object to betracked; each of the plurality of tags including a memory to receiveobject-related information pertaining to the different object to betracked and being configured so as to generate and transmit a tag signalindicative of the object-related information;

a plurality of primary base stations, each coupled to a pair ofsecondary base stations so as to define a tag detecting cell; theplurality of primary base stations defining overlapping cells; each ofthe primary and two secondary base stations being configured to receivethe tag signals, yielding three received signals to be processed by theprimary base station yielding the location of the tag within the cell;and

a central server coupled to the plurality of primary base stations forreceiving at least one of the tag signals and the location of the tagwithin the cell and including an expert agent for tracking the pluralityof tags within the overlapping cells.

Other objects, advantages and features of the present invention willbecome more apparent upon reading the following non restrictivedescription of illustrative embodiments thereof, given by way of exampleonly with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the appended drawings:

FIG. 1 is a bloc diagram of a wide area object and large capacitytracking system according to an illustrative embodiment of a firstaspect of the present invention;

FIG. 2 is a perspective view of a tag according to an illustrativeembodiment of a second aspect of the present invention;

FIG. 3 is a perspective view illustrating the tag from FIG. 2, attachedto a baggage and the portable control unit from FIG. 1;

FIG. 4 is a perspective view of the tag recording unit from FIG. 1;

FIG. 5 is a schematic view illustrating an example of configuration ofthe primary and secondary base stations from FIG. 1;

FIG. 6 is a perspective view illustrating the operation of the portablecontrol unit from FIGS. 1 and 3;

FIG. 7 is a perspective view illustrating the tag tracking terminal andtag recovery apparatus from FIG. 1;

FIG. 8 is a functional bloc diagram of the wide area object and largecapacity tracking system from FIG. 1;

FIG. 9 is a perspective view illustrating the registering of baggage andtag validation using the portable control unit from FIGS. 1 and 3;

FIG. 10 is a perspective view illustrating the tracking of baggages on aconveyor using the system from FIG. 1;

FIG. 11 is a bloc diagram of the system from FIG. 1, incorporating aback-up server;

FIG. 12 is a schematic view of the system from FIG. 1, illustrating themulti-layer architecture of the system; and

FIG. 13 is a schematic view illustrating a tag localization methodaccording to a third aspect of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Turning now to FIG. 1 of the appended drawings, a wide area object andlarge capacity tracking system 10 according to an illustrativeembodiment of the present invention is illustrated.

According to the illustrative embodiment, the system 10 is in the formof a wireless system allowing to track baggage 6, bags (not shown),persons (not shown), etc. in real-time in airports and from airports toairports via the use of wireless tags 8 (see FIG. 2).

The wide area and large capacity intelligent baggage tracking system 10comprises a tag recording unit 12, a central server 14, a plurality ofprimary base stations 16 coupled to the server 14, two secondary basestations 18 for each of primary base station 16 and being coupled to theprimary base station 16, portable control units 20 configured so as tobe selectively coupled to the central server 14, tag tracking terminals22, tag recovery apparatus 24 and a tag inventory managing server 26.

As illustrated in FIG. 2, each tag 8 includes a casing 28 and a loop 30secured to the casing 28 at one end and releasably mounted in the casing28 at its other end via a releasable locking mechanism (not shown).Alternatively, the loop 22 may be replaced by another attaching means.Of course, both ends of the loop 30 may alternatively be releasablymounted to the casing 28. FIG. 3 illustrates a tag 8 attached to thehandle 34 of a baggage 6.

Each tag 8 includes a power source in the form of a battery (not shown),a controller (not shown), a memory (not shown), a receiver (not shown),and a transmitter (not shown) embodied, for example, in electroniccircuitry comprised within the casing 28.

The controller, receiver and transmitter allow a tag 8 to communicatewith primary and secondary stations 16-18, the recording unit 12 andother wireless components of the system 10.

More specifically, each tag 8 is configured so as to:

-   -   a) transmit a request signal after its free end is locked in the        body 28 by the locking mechanism;    -   b) receive from the tag recording unit 12 an identification code        and a list of checkpoints;    -   c) be locked or unlocked;    -   d) emit a visual signal via, for example, LEDs (Light Emitting        Diode) 32 mounted to its casing 28;    -   e) communicate with the tag recording unit 12, the portable        control units 20, and the tag recovery apparatus 24;    -   f) transmit an identification code at predetermined intervals;    -   g) verify the concordance of the checkpoints and send an alarm        signal if there is any discrepancy;    -   h) emit a visual signal, such as the LEDs 32 flashing, upon        receiving a triggering signal from a nearby portable control        unit 20;    -   i) emit its identification code and information stored in its        memory, for example, upon request of a nearby portable control        unit 20;    -   j) emit a visual signal, such as the LEDs 32 flashing, upon        receiving a triggering signal from a primary station 16;    -   k) accept and receive verification and diagnostic command        signals from the tag recovery apparatus 24; and    -   l) unlocked the locking mechanism whenever an appropriate signal        is transmitted by the tag recovery apparatus 24.

Of course, the tags can be configured with other visual signal emittersthan LEDs 32. Also, it can be modified to emit sound signals instead ofvisual signals.

The operation of each tag 8 is as follows. Upon activation of the tag 8by the tag recording unit 12, the tag 8 broadcasts its identificationcode at a predetermined time interval. The tag 8 then puts itself in alistening mode for a brief time after broadcasting its identificationcode, before putting itself in a sleep mode. The listening mode allowsthe system 10 to communicate with the tag 8 to obtain informationtherefrom or to modify some of its operating parameters.

The checkpoints stored in the tag memory include a sequential list ofthe primary base stations 16 that the tag 8 is expected to meet alongits path. The checkpoints list allows each tag 8 to assess its ownprogression in the airport towards its final destination. Each tag 8 isconfigured so that any discrepancy between its expected path and the tag8 actual path triggers an alarm signal recognizable by the system 10.

The electronic circuitry of the tag 8 and the locking mechanism are socoupled that any breakage or attempt to break the loop 30 after wilfullocking of the locking mechanism triggers an alarm signal, that is to bereceived by the system 10, indicative of the breakage

Other features and functions of the tags 8 will become more apparentupon reading the description of the system 10 and of its differentcomponents.

The tag recording unit (TRU) 12 will now be described in more detailswith reference to FIGS. 1 and 4. The TRU 12 is in the form of a computerterminal wirelessly coupled to the central server 14. Of course, thecomputer terminal 12 can also be connected to the central server 14 viacables.

The computer terminal 12 includes a visual display 34, an input means inthe form of a keyboard 36 allowing a person to associate information toa selected tag 8, a tag input port 38 for wireless communication with atag 8, and a wireless receiver/transceiver unit (not shown) including anantenna 39 for wireless communication with the central server 14. Thevisual display can take many forms including a plasma screen and a pixelscreen.

The TRU 12 is positioned on or near the baggage registering desk 40 (seeFIG. 9) and allows to activate tags 8.

The TRU 12 is configured so as to:

-   -   a) display on its visual display 34 a user-interface;    -   b) detect the signal from a tag positioned onto the tag port 38;    -   c) associate the detected identification signal and the        corresponding baggage 6 to a specific traveller;    -   d) upon receiving a command from the operator via the input        means 36, transmit via the tag port 38 a communication code        triggering the tag 8 to begin transmitting its identification        code at a predetermined interval;    -   e) to verify, upon activation of a tag 8, the integrity of the        signal transmission from the tag 8; and    -   f) when the activation of a tag is successful, to transmit to        the central server 14 information stored in the tag memory or        related to the tag 8.

The TRU 12 generates identification code according to a predeterminedalgorithm. For reliability purposes, the TRU 12 compares periodicallythe list of generated codes stored in its memory to the ones receivedand stored by the central server 14.

Of course, more than one TRU 12 is usually provided with each system 10,one for each baggage registering desk 40 for example.

Turning now to FIGS. 1 and 5, the primary and secondary base stations16-18 will now be described in more details.

Each primary base station (PBS) 16 defines a cell 42 covering part ofthe baggage handling area 44. For example, each cell defines a circulararea having a 100 m radius, yielding a 31 400 m² area cell. The PBS 16are so positioned that the cells 42 are overlapping therefore allowingto cover the entire baggage handling area 44.

Each PBS 16 includes a controller (not shown), a memory (not shown), areceiver (not shown), a transceiver (not shown) and control circuit (notshown).

The PBS 16 are configured to wirelessly communicate through threechannels: a first one for communication with the tags 8, the second onefor communicating tag identification codes and other tag parameters tothe central server 14, and a third one for communication between theprimary base stations 16, secondary base stations 18 and the portablecontrol units 20. The communication protocol used is IEEE 802.11. Ofcourse, other communication protocol may also be used. The system 10 mayallow simultaneous communication between about 128 PBS 16 and portablecontrol units 20 in direct spread spectrum (DSS). Of course, othercommunication protocols can be used. Alternatively, since the primaryand secondary base stations 16-18 are immobilized, they can beinterconnected via cables (not shown).

Each primary base station 16 is configured to:

-   -   1. communicate with the central server 14 so as to obtain the        list of active tags 8;    -   2. detect the coded signal of each tag 8 entering its cell 42;    -   3. receive and store information incoming from the SBS 18;    -   4. determine the position of tags 8 within a cell 42;    -   5. transmit to the central server 14 tags' coordinates or other        tag-related information such as checkpoint-related codes;    -   6. signal the lost of a tag 8 and estimate the probable position        of the tag 8 using the last known position;    -   7. transmit frequent query signals to communicate with a lost        tag 8;    -   8. manage the communication with tags 8 and with two SBS 18        present within the cell 42;    -   9. manage and relay to the central server 14 communications        incoming from the portable control units 20; and    -   10. allow communication between PBS 16.

Each secondary base station 18 is configured to:

-   -   1. dynamically receive a list of tags 8 from the cell's PBS 16;    -   2. record and relay to the PBS within the same cell 42, the time        of arrival and identity of each tag 8 within the cell 42; and    -   3. relay commands from then cell's PBS 16 whenever the wireless        communication is unclear.

More specifically, the PBS 16 queries all tags 8 within its cell 42within a very short frame of time, including receiving a request fromthe central server 14, query the tags 8 within the cell 42, and beginsearching procedure for missing tags. For example, the system 10 allowsto read more than 10 000 tags 8 in a cell in less than one second.

The PBS 16 together with the two SBS 18 within a cell 42 achieve thelocalisation of tags using Time Difference of Arrival (TDOA) 84,Received Signal Strength (RSS), and Artificial Neural Network (ANN) 86techniques using signals received from the tags 8.

In addition to the three above-mentioned techniques a Modified Time ofArrival (M-TOA) technique is also used.

The provision of ANN allows freeing the system 10 from huge databasestraditionally used to map the electromagnetic field distribution of anarea including moving objects such as tags 8. Knowing this distributionand other related data allows averaging the environment of a mobileobject and deducing certain information about the tag's position.

As illustrated in FIG. 13, the ANN 84 and the TDOA 86 technique is usedto accurately locate tags 8 and yields relatively simple networkarchitecture. Before processing the tag signals in the ANN 84, twopre-process are performed: a hyperbola computation, a fast taglocalisation using the TDOA 86 and correlation between the signalamplitudes detected by the PBS 16 and SBS 18.

As it is well known in the art, a learning process is first executed bythe ANN 84 to established prediction parameters and to adjust theirinternal free parameters This adjustment allows minimizing theprediction errors by minimizing the performance function of the neuralnet (quadratic error average). Every entry in the ANN 84 is indicativeof the multiple tag path time delays as received by the PBS 16 and SBS18.

Once the localisation of tags 8 is achieved, the resulting coordinatesof each tag 8 are sent to the agent expert 76 (see FIG. 12) of thecentral server 14 for tag grouping or bundle processing. Thislocalisation procedure can be executed many times each second on aspecific tag 8 or group of tags to obtain an improved precision onits/their localisation.

Since TDOA, RSS and ANN techniques are believed to be well known in theart, it will not be described herein in more details. Alternatively,other techniques can be used to locate tags.

Since the PBS 16 can be located outside the reach of the central server14, they are equipped with an inter-PBS communication module allowingPBS 16 located outside the reach of the central server 14 to communicatetherewith via the nearer PBS 16 which relay the information from theout-of-reach PBS 16 to the central server 14. Similarly, the PBS 16allows the portable control units 20 to communicate with the centralserver 14. The system topology is of the Extended Service Set (ESS)-typeincluding multiple access points (AP). Of course, other system topologycan alternatively be implemented.

The portable control unit (PCU) 20 is in the form of a small module thata person can wear around the forearm (see FIG. 3) or alternatively atthe waistband or on the shoulder for example.

The PCU 20 includes an output means in the form of a text or graphicaldisplay screen 46, an input means in the form, for example, of akeyboard 48, a receiver (not shown), and a transceiver (not shown). ThePCU 20 is configured so as to be wirelessly coupled to the system 10,and more specifically to the central server 14, and PBS 16.

The PCU 20 is also configured so as to allow:

-   -   1. communication with the central server 14, for example to        retrieve a list of tags 8 boarding on or unloading from a plane;    -   2. upon receiving input command from a user via the keyboard 48,        sending a signal to tags 8 boarding on or unloading from a        selected plane requesting the tags 8 to identify themselves to        the PCU 20 and to send both their source and destination;    -   3. comparing the information received from the queried tags 8        with pre-stored information;    -   4. displaying to the operator the result of the previous        comparing steps, providing a list of missing tags 8;    -   5. in cases of missing tags 8, forwarding to the central server        14 the list of missing tags 8, so that the central server 14        initiates a retrieving procedure; and    -   6. if all tags acknowledge their presence on the right plane,        sending, upon receiving command from the operator via the input        means 48, a confirmation signal triggering a sleep mode in the        onboard tags 8. The sleep mode is active until an activation        code is sent to each tag 8 inactivated by the sleeping mode.

The PCU 20 is programmed with a tag-searching mode. This mode can beactivated, for example, when a tag 8 does not respond between tocheckpoints or if a tag 8 sends a distress signal. The central server 14then initiates a tag search. If the missing tag 8 is retraced by thesystem 10, an operator having a PCU 20 is sent to retrieve thecorresponding missing baggage 6 (see FIG. 3). The coordinates of missingtags 8 are downloaded to the PCU 20 at a predetermined frequency. Agraphical user interface is displayed on the screen 46 to allow theoperator to evaluate the location of broadcast of the tag 8. The PCU 20can be used, after retrieving a tag 8, to acknowledge the retrieval tothe central server 14.

The PCU 20 can also be used to manage baggage 6 incoming from a conveyor50 (see FIG. 6) or from a trolley to be loaded into a container 52. ThePCU 20 allows knowing the number and location of each baggage 6 loadedin the container 52. Indeed, knowing the capacity of the container 52,which is inputted in the PCU 20, and the sequence of loading of thecontainer 52, the position of each tag 8 in the container 52 can bedetermined.

Turning now to FIG. 7, the tag tracking terminal 22 and tag recoveryapparatus 24 will be described in more detail. Each of the tag trackingterminal 22 and tag recovery apparatus 24 are either wirelessly coupledto the central server 14 or connected thereto via cables.

The tag tracking terminal 22 is in the form of a touch screen 54 mountedon a stand 56. The touch screen 54 allows a person to consult with thecentral server 14 so as to inquire the location of a specific tag 8. Ofcourse, more than one tag tracking terminal 22 can be provided with thesystem 10. The tag tracking terminal can take other forms. For example,a dedicated telephone line, provided with a voice-recognition algorithmand voice synthesiser, can allow a user to query the central server 14about the location of a specific tag.

The tag recovery apparatus (TRA) 24 includes an output means in the formof a display screen 58, an input means in the form of a series ofbuttons 60, a tag depository compartment 62, and a guarantee ticketdistributor 64.

The output and input means 58-60 can take other form. For example, theinput means can be in the form of a keypad (not shown), or the displayscreen 58 can be in the form of a touch screen (not shown).

The TRA 24 includes a controller (not shown) configured so as to displayon the screen 58 a user menu offering to the user different form ofretribution in exchange for a tag 8.

The TRA 24 retrieves a list of tag's identification codes from thecentral server 14. This list can be obtained from the origin or transitairport.

The input means 60 allows the user to input an unlocking code given tohim during the baggage-registering step. Once the code is entered andvalidated by the TRA 24, the TRA 24 transmits to the corresponding tag 8an unlocking code that causes the unlocking of the tag 8.

A baggage tracking system according to the present invention providesfor many ways of managing the tags 8.

For example, a tag 8 can be obtained in exchange of a certain amount ofmoney at the baggage-registering step. The same amount can then berecuperated from the TRA 24 in exchange of the tag 8. The TRA 24 can beconfigured to offer and provide the amount to the user in many formsincluding cash, discount coupon for a flight, etc. Alternatively, a usermay be able to purchase his own tags 8 that are activated uponregistering its baggage and unlock or simply deactivated by inputtingthe unlocking code into the TRA 24. The TRA 24 allows an efficientmanagement of tags 8 and provides a means for the airlines or theairport for not bearing the expenses related to the tags 8.

The TRA 24 is configured to allow recharging the recuperated tags 8 anddiagnostic defects and sort tags 8 accordingly.

The TRA 24 forwards information about the recuperated tags 8 to thecentral server 14.

The tag inventory-managing server (TIMS) 26 is remotely connected to thecentral server via the Internet. Alternatively, it can be connected viaanother dedicated computer network or be directly coupled to the centralserver 14. In cases where systems such as system 10 are implemented ondifferent airports, the TIMS 26 allows receiving, storing and forwardingto remote system 10, information about each tags 8 tracked by eachsystem 10. This allows the system 10 implemented in a destinationairport to continue tracking tags 8 that have been activated in anotherairports.

Additionally, the TIMS 26 may store in a memory the location of all tags8 that are tracked by each local system 10. Knowing information relatedto each tag 8, such as its position, the airports from which it has beenissued or the airline that activated it, the TIMS 26 can manage forexample, their rerouting towards the issuer of the tag 8.

Other features and characteristics of the system 10 will become moreapparent upon reading the following description of the operation of thesystem 10 given with reference to FIGS. 3 and 6 to 10.

As illustrated in FIG. 9 and discussed hereinabove, a tag 8 is activatedusing the TRU 12 and tied to the handle of each baggage 6 that isregistered at one of the baggage registering desk 40. The baggage 6 isthen deposited onto a conveyor to be sent to a predetermined loadingdock (not shown).

During the activation of a tag 8, information pertaining to the owner ofthe baggage 6 to which the tag is associated is stored in the tagmemory. This information includes, for example, codes identifying theboarding, transit and destination airports, the airline, and the ownerof the baggage.

At the end of the activation process, the TRU 12 sends the taginformation to the central server 14.

In addition to activating the tag 8, the TRU 12 verifies the integrityof each tag 8 before its activation.

As can be seen from FIG. 10, the tag 8 corresponding to each baggage 6is tracked along its path by PBS 16 and SBS 18 (not shown). Moreover,each tag 8 verify the conformity of its itinerary by comparing thesequence of PBS 16 met along its path to the checkpoints stored in itsmemory during its activation. It is to be noted that the system 10allows to reprogrammed a tag 8 with new checkpoints while it travelsfrom the baggage registering desk 40 to the loading dock. Of course, allwireless communications of the system 10 are secured so as to preventmalicious attempts to tamper with the system 10.

The frequency of tag queries is adjusted in accordance with manyfactors, such as: the configuration of the baggage sorting system, theconveyors' speed, the number of activated tags, the wirelesscommunication frequency band, the nature of the object or person towhich the tags are tied, etc. Indeed, the system can be used to trackbaggage, bags, employees, trolleys, travellers, etc. For example, insome instances, a need could arise for tracking a specific baggage orperson between shorter time intervals so as to know more precisely itspath.

The baggage 6 continue their itinerary towards a baggage loading dock(see FIG. 6) where their presence is verified and acknowledged by thePCU 20 as explained hereinabove.

The PCU 20 allows detecting the vicinity of every tag 8 within itsrange. The range can be adjusted by calibration of the PCU 20.

Whenever the system 10 looses track of a tag 8 between checkpoints N andN+1, a two-level security system is activated.

The first level of security involves the tags 8. A tag 8 that does notdetect the checkpoint N+1 following the checkpoint N sends a distresssignal to be detected by the system 10. The distress signal is thenregistered by the system 10. The system 10 responds by activating arequest task to an expert agent 76 configured to take in charge the tag8 that sends distress messages. The expert agent 76 automaticallyupdates information about the tag 8 such as its position, the powerlevel of the transmitted signal, the power level of the battery. Whilethe expert agent 76 is managing the tag 8, the system 10 informs theoperator about the problem and then another operator equipped with a PCU20 is sent to find the tag 8.

The second security level involves an expert agent 76 (see FIG. 12)implemented in the central server 14. The functions of the expert agent76 include:

-   -   1. receiving from an operator parameters allowing the creation        of tags dynamic nodes;    -   2. transmitting to primary and secondary base stations 16-18        commands allowing to assemble and manage tags 8 by dynamic node        bundles;    -   3. receiving tracking parameters, such as identification code of        tags 8, its position, the corresponding flight number, the tag's        destination, etc., allowing real-time formation of dynamic nodes        and tracking of tags 8 in the airports;    -   4. modifying the tag 8 communication parameters;    -   5. interacting with other expert agents to exchange tag-related        information;    -   6. via a user-interface of the central server 14, allowing an        operator to regulate tag operating parameters and observe tag        movement in the airport;    -   7. managing entries and exits of tags 8 in the system 10;    -   8. communicating with tag recovery apparatus 24 to determine the        tag flow in the airport;    -   9. receiving alarm signals from tags 8 and primary base stations        16 and managing lost tag searching procedures; and    -   10. performing system 10 diagnostic.

Returning to the second security level, the disappearance of a tag 8between two checkpoints unbalances the node that includes the tag. Theexpert agent 76 then initiates a search. The search includes:

-   -   1. the primary and secondary stations 16-18 requesting an        emergency identification of the tag 8 and listening to the        corresponding communication channel;    -   2. once the tag 8 and the corresponding baggage 6 have been        retraced and their position determined, sending an operator with        a PCU 20 to intercept the baggage 6 (see FIG. 3), the        coordinates of the baggage 6 being sent to the PCU 20 and        displayed on its screen 4; and    -   3. if no acknowledgement signal is received from the missing tag        8, the system 10 determining the last known position thereof,        which is between the N and N+1 checkpoints, and prompting an        operator with a PCU 20 to go searching for the missing baggage 6        between the two checkpoints.

Returning briefly to FIG. 8, the information pertaining to the tags 8and their respective control code are transferred from the boardingairports to the transit airport and then to the destination airport viathe TIMS 26.

At the destination airport, an operator having a PCU 20 broadcast asignal to reactivate all incoming tags 8, then in a sleep mode, andcompare the list of detected tags 8 to the list transmitted by centralserver 14 of the destination airport, as received by the TIMS 26. Thesystem 14 from the destination airport then starts tracking and managingthe incoming tag 8 as discussed hereinabove.

Alternatively, the signal to reactivate all incoming tags 8 can bebroadcast by a PBS 16 nearby the tag arrival area.

Arrived at their destination, the tags 8 receive a signal from the lastPBS 16, referred herein as the discharge PBS 16′ (see FIG. 7). The cell42 defined by the discharge PBS 16′ include the baggage recoverycarousel (not shown). The LEDs 32 from each tag 8 in this cell thenflash, or display another visual signal, inviting the owner of thebaggage 6 to introduce the unlocking code into the TRA 24.

An object tracking system according to the present invention allowsimplementing simple solutions to three (3) types of system's fault.

A hardware's fault is dealt with by rapidly replacing the faulty pieceof hardware.

A illustrated in FIG. 11, a system software's fault is minimized bystoring dynamically all recorded data on a database 68 stored on anindependent memory device or server coupled to the central server 14. Aback-up server 66, which is also coupled to the database 68, is coupledto the central server 14 and is configured to monitor the central server14 and to mirror all the configuration of the central server 14. Anyhardware's or software's fault is detected by the backup server 66 whichthen continue the operation of the system 10, having access to thedatabase 68.

The use of encoding and decoding for all communications and the use of afirewall allows minimizing hacking of the system 10 and maliciousattempts to tamper with the system 10.

The use of wireless communication provides for an easy implementation ofthe system 10. More specifically, the central server 14, PBS 16, SBS 18communicates using the IEEE 802.11 (WLAN) protocol via the IndustrialScientific and Medical (ISM) channel at 2.45 GHz. The tags 8 communicatewirelessly at 2.45 GHz.

As illustrated in FIG. 12, the system 10 is implemented in three layers:a radio-frequency (RF) layer 70, a software layer 72 and a service layer74.

The RF layer 70 comprises the wireless components of the system 10forming a wireless local area network (WLAN). The system 10 allowsprimary base station 16 that are out of range of the central server 14to communicate with the central server 14 via other PBS 16.

The software layer 72 is implemented in the central server 14 andincludes the expert agents (EA) 76 and allows creating and managingdynamic nodes. The tags 8 are regrouped in the system 10 by the EA 76according to their positions, the characteristics of their environment(surrounding interference, level of noise, etc.), the sequence ofvalidation, the distance between baggage 6, their corresponding flightnumber and airline, their destination and transit, the intensity oftheir signal as received by the system 10, etc. This grouping virtuallylinks the baggage 6 in the system 10, allowing their tracking andmanagement. The grouping is said to be dynamic since a specific link canbe modified at any given time. Depending on the nature of the objectassociated to a tag 8, the central server 14 processes the datainformation related to each tag 8 using a specific service module 78-82.

As illustrated in FIG. 12, the service layer 74 includes differentservice modules that can be used such as the security tracking module78, baggage tracking module 80 and resources management module 82. It isto be noted that the expression “module” should be construed in a broadsense, included, but not limited to, a series a logic instructionprogrammed in the central server 14 allowing to process data informationto achieve an expected result.

The security tracking module 78 allows to manage security aspect relatedto circulation of objects, goods, and people within predetermined areas.The resources management module 82 allows managing inventory andcirculation of equipment and employees for example.

The number and location of the PBS 16 depend on the configuration anddimension of the baggage handling system, including the conveyorsconfiguration and location 50. The number of PBS 16 is related to theadditional services desired: baggage tracking, security tracking orresources management. The wireless protocol used to implement the system10 gives the maximum electric field that can be used for indoor andoutdoor environment. The system is configured so as to respect widelyadopted protocol, national or international rules and regulations onradio signal used to avoid generating interferences on others appliancesand protect human body. The protocol used affects the size of cells 42in the system 10.

For example, for an average size airport such as the Dorval airport inMontreal and the JFK airport in New York, in the international flighthub, the dimension of the luggage handling area is about 1000 m by 650 m(650 000 m²). About 50 000 baggages per day travel on this area.Considering the maximum amplitude of the electromagnetic field allowedby the IEEE 802.11 standard, ones can find that maximum size radius ofcells should be around 100 meter for and indoor environment anddepending of the configuration for free space signal propagation, thethickness and the type of material the walls are made of. In thisconfiguration, different types of protocols can be used to allowtracking and communication to more than 100 000 baggage within someseconds (less than 3 seconds for some protocols) without any conflictbetween tags.

The system 10 can be deployed on different sections in an airport suchas two hubs (not shown). Those two hubs are then linked together via thecentral server 14 by providing PBS 16 between the hubs.

When the PBS 16 and SBS 18 in a given cell 42 (FIG. 5) send querysignals to tags 8 in the cell 42, each tag 8 responds sequentially. Thecentral server 14 controls the exact time when each tag 8 has to respondto the system 10. The size of the communication code between a basestation 16 or 18 and a tag 8, the frequency of the carrier wave, and thecommunication protocol determine the maximum capacity in terms of tagnumber that can be manage by the system 10 so as to preventcommunication crashes.

Even though the illustrative embodiment of a system 10 according to thepresent invention includes a central server 14, the functionalitythereof can be implemented on one or some of the primary and/orsecondary base stations 16-18.

Also, the tag recording unit 12 is optional since the system 10 can beused with tag having a memory pre-programmed with information related tothe object to which it will be attached.

Of course, the tags 8 can take many forms allowing to store informationand transmit signal pertaining to such information. Tags 8 can also bepermanently attached to the object.

The wireless communication signal can also take many forms, and so isthe communication protocol used.

An object tracking system according to the present invention can be usedto track many kinds of objects and life forms, including people. It canbe used, for example, as an inventory managing system. Also, thetracking system may be used to track objects in a single premises.

Although the present invention has been described hereinabove by way ofpreferred embodiments thereof, it can be modified without departing fromthe spirit and nature of the subject invention, as defined in theappended claims.

1. A wide area object tracking system comprising: at least one primarybase station and a pair of secondary base stations; each of said pair ofsecondary base stations being so coupled to said primary base station soas to define a tag detecting cell; each of said primary and twosecondary base stations being configured to receive a tag signalbroadcast from a tag attached to an object to be tracked, yielding threereceived signals indicative of the location of said tag within saidcell; whereby a plurality of overlapping said tag detecting cell in agiven space would allow tracking objects at any place within said givenspace.
 2. A system as recited in claim 1, comprising a plurality ofprimary base stations.
 3. A system as recited in claim 2, wherein eachof said plurality of primary base stations including an inter-primarybase station communication system allowing communication between any oneof said plurality of primary base stations.
 4. A system as recited inclaim 3, further comprising a central server to which at least one ofsaid plurality of primary base stations is coupled; said inter-primarybase station communication system allowing to relay a communication fromany one of said plurality of primary base stations to said centralserver.
 5. A system as recited in claim 4, wherein a first part of saidplurality of said primary base stations is located in a first premisesand a second part of said plurality of primary base stations is locatedin a second premises; said first and second parts of said plurality ofprimary base stations being respectively coupled to said central servervia first and second additional primary base stations.
 6. A system asrecited in claim 4, further comprising a portable control unitconfigured to be coupled to at least one of said plurality of primarybase stations; said inter-primary base stations communication systemallowing to relay a communication between said portable control unit andsaid central server.
 7. A system as recited in claim 1, furthercomprising a central server coupled to said at least one primary basestation.
 8. A system as recited in claim 7, wherein said at least oneprimary base station is configured so as to communicate using threecommunication channel; a first communication channel being used tocommunicate with said tag; a second communication channel being used tocommunicate with said central server; and a third communication channelbeing used to communicate with at least one of other primary basestations, said pair of secondary base stations, and a portable controlunit.
 9. A system as recited in claim 8, wherein said first, second, andthird communication channels are secured.
 10. A system as recited inclaim 8, wherein said first, second, and third communication channelbeing implemented under the IEEE 802.11 protocol.
 11. A system asrecited in claim 7, wherein said central server includes auser-interface to display tag movements in said space.
 12. A system asrecited in claim 7, further comprising at least one tag recording unitfor activating said tag and being coupled to said central server.
 13. Asystem as recited in claim 12, wherein activating said tag includesgenerating an identification code and storing said identification codein at least one of i) a memory of said tag recording unit, ii) a memoryof said at least one tag, and iii) a memory of said central server. 14.A system as recited in claim 13, wherein said tag recording unit isfurther configured to compare identification codes stored in said memoryof said central server with identification codes stored in said memoryof said tag recording unit.
 15. A system as recited in claim 12, whereinsaid tag recording unit is wirelessly coupled to said central server.16. A system as recited in claim 12, wherein said tag recording unitincludes at least one of a visual display, a tag input port forcommunication with said tag, and input means allowing a person toassociate information to a tag.
 17. A system as recited in claim 7,further comprising a tag tracking terminal coupled to said centralserver for retrieving from said central server object-relatedinformation.
 18. A system as recited in claim 17, wherein said tagtracking terminal is wirelessly coupled to said central server.
 19. Asystem as recited in claim 17, wherein said tag tracking terminalincludes a display screen or a touch screen.
 20. A system as recited inclaim 17, wherein said tag tracking terminal includes a telephone.
 21. Asystem as recited in claim 7, further comprising a tag recoveryapparatus coupled to said central server.
 22. A system as recited inclaim 21, wherein said tag recovery apparatus is wirelessly coupled tosaid central server.
 23. A system as recited in claim 21, wherein saidtag including a rechargeable power source; said tag recovery apparatusbeing configured so as to recharge power source.
 24. A system as recitedin claim 21, wherein said tag recovery apparatus includes an means forinputting a tag unlocking code, a tag depository compartment forreceiving tags, and a guarantee ticket distributor to provide aguarantee ticket in exchange for a tag provided in said tag depositorycompartment.
 25. A system as recited in claim 24, wherein said tagrecovery apparatus being configured so as to forwards information tosaid central server about tags received in said tag depositorycompartment.
 26. A system as recited in claim 24, wherein said guaranteeticket being selected from the group consisting of cash and discountcoupon.
 27. A system as recited in claim 26, wherein said tag is rentedand said guarantee ticket is issued in exchange for said rented tag. 28.A system as recited in claim 24, further comprising at least one tag tobe attached to an object to be tracked; said at least one tag includinga casing and attaching means releasably secured to said casing; saidattaching means including a loop having two ends and being secured tosaid casing at one end and releasably mounted in said casing at itsother end; said other end being releasably mounted in said casing via areleasable locking mechanism; said tag recovery apparatus beingconfigured to receive a list of central server tag unlocking codes fromsaid central server for comparison with inputted tag unlocking code bothto be used in assessing if said releasable locking mechanism should beunlocked.
 29. A system as recited in claim 24, wherein said tag recoveryapparatus includes a display screen and a controller configured so as todisplay on said display screen a menu offering different form ofretribution in exchange for tags.
 30. A system as recited in claim 7,further comprising a tag inventory managing server coupled to saidserver; said tag inventory managing server being configured forcommunication with a remote central server.
 31. A system as recited inclaim 30, wherein said central server is located in a first airport andsaid remote central server is located in a second airport; whereby saidtag inventory managing server allows to securely interconnect saidcentral server and said remote central server for communicationtherebetween.
 32. A system as recited in claim 30, wherein said taginventory managing apparatus is remotely connected to said centralserver via a network.
 33. A system as recited in claim 32, wherein saidnetwork is selected from the group consisting of a dedicated network,and the Internet.
 34. A system as recited in claim 7, wherein saidcentral server is coupled to a memory device for storing saidobject-oriented information.
 35. A system as recited in claim 34,further comprising a back-up server coupled to said central server, tosaid memory device, and to said at least one primary base server formirroring and monitoring said central server; said back-up server beingconfigured to detect a fault of said central server and to continue theoperation of said central server whenever said fault is detected.
 36. Asystem as recited in claim 1, wherein said primary base station includesat least one of a controller, a memory, a receiver, and a transceiver.37. A system as recited in claim 1, wherein said pair of secondary basestation being is wirelessly coupled to said at least one primary basestation.
 38. A system as recited in claim 1, further comprising: atleast one of said tag to be attached to an object to be tracked; said atleast one tag including a power source, and a memory to be programmedwith object-related information pertaining to said object to be tracked,and being configured so as to generate and transmit via a transmittersaid tag signal indicative of said object-related information.
 39. Asystem as recited in claim 38, wherein said object-related informationis selected form the group consisting of a code identifying a boardingairport, a code identifying a transit airport, a code identifying adestination airport, and information about the owner of said object. 40.A system as recited in claim 38, wherein said at least one tag includesa casing and attaching means releasably secured to said casing.
 41. Asystem as recited in claim 40, wherein said attaching means includes aloop having two ends and being secured to said casing at one end andreleasably mounted in said casing at its other end.
 42. A system asrecited in claim 41, wherein said other end is releasably mounted insaid casing via a releasable locking mechanism.
 43. A system as recitedin claim 42, wherein said at least one tag being configured to transmita request signal after said other end is locked in said lockingmechanism.
 44. A system as recited in claim 38, wherein said at leastone tag is configured to emit a visual signal.
 45. A system as recitedin claim 38, wherein said at least one tag further includes a receiver.46. A system as recited in claim 38, wherein said memory is further tobe programmed with tag-related information; said at least one tag beingfurther configured so as to generate and transmit via said transmittersaid tag signal indicative of said object-related information and saidtag-related information.
 47. A system as recited in claim 46, whereinsaid tag-related information includes at least one of the power level ofsaid tag signal, and the battery level of said tag.
 48. A system asrecited in claim 1, further comprising at least one portable controlunit wirelessly coupled to said system and being configured to receiveat least one of said tag signal and object-related information.
 49. Asystem as recited in claim 48, wherein said portable control unit beingconfigured to trigger a sleep mode on said tag.
 50. A system as recitedin claim 49, wherein said portable control unit being configured tore-activate a tag in a sleep mode.
 51. A system as recited in claim 48,further comprising a central server, wherein said portable control unitbeing configured to be coupled to said central server.
 52. A system asrecited in claim 51, wherein said at least one tag includes a pluralityof tags; said portable control unit allowing to request selected tagsfrom said plurality of tags to broadcast their respective tag signals tobe received by said portable control unit.
 53. A system as recited inclaim 52, wherein said portable control unit includes pre-storedobject-related information; said portable control unit being configuredfor comparing said pre-stored object-related information to saidobject-related information to create a list of missing tags.
 54. Asystem as recited in claim 53, wherein said pre-stored object-relatedinformation being received from said central server.
 55. A system asrecited in claim 53, wherein said portable control unit being configuredto send said list of missing tags to said central server; said centralserver being configured to initiate a tag retrieving procedure when saidlist of missing tags is not empty.
 56. A system as recited in claim 51,wherein said object-related information includes information concerninga plane to be boarded by said at least one tag or a plane from whichsaid at least one tag is unloaded; said selected tag being selected onthe basis of said information concerning said plane to be boarded bysaid at least one tag or said plane from which said at least one tag isunloaded.
 57. A system as recited in claim 1, wherein said object isselected from the group consisting of baggage, goods, people, andanimal.
 58. The use of a system as recited in claim 1 in an inventorymanaging system.
 59. A wide area object tracking system comprising: atleast one tag; each of said at least one tag being to be attached to anobject to be tracked; said at least one tag including a memory toreceive object-related information pertaining to said object to betracked or tag-related information and being configured so as togenerate and transmit a tag signal indicative of at least one of saidobject-related information and said tag-related onformation; a centralserver including a memory for storing said object-related information; atag recording unit coupled to said central server and being configuredto program said memory of said at least one tag with said object-relatedinformation; at least one primary base station coupled to said centralserver; said at least one primary base station being coupled to a pairof secondary base stations so as to define a tag detecting cell; each ofsaid primary and two secondary base stations being configured to receivesaid tag signal, yielding three received signals to be processed by saidprimary base station yielding the location of said tag within said cell;said primary base station being configured to forward said location ofsaid tag within said detecting cell to said central server; and at leastone portable control unit wirelessly coupled to at least one of saidcentral server and said at least one primary base station; said at leastone portable control unit being configured to receive at least one ofsaid tag signal, said object-related information and said location ofsaid tag within said detecting cell.
 60. A wide area object trackingmethod comprising: activating at least one tag to be attached to anobject to be tracked causing said at least one tag to broadcasting a tagsignal indicative of information pertaining to at least one said objectto be tracked and said at least one tag; providing at least one primarybase station and a pair of secondary base stations; said pair ofsecondary base stations being so coupled so as to define a tag detectingcell with said primary base stations; each of said at least one primarybase station and said pair of secondary base stations coupled thereoflistening for tag signals within said tag detecting cell; and upondetection of one of said tag signals by said at least one primary basestations and said pair of secondary base stations coupled thereof,yielding three respective received signals, using said three respectivereceived signals to determine the location of said at least one tagwithin said tag detecting cell.
 61. A method as recited in claim 60,wherein said at least one tag putting itself in a listening mode for afirst period of time following said tag broadcasting a tag signal andbefore putting itself in a sleep mode for a second period of time.
 62. Amethod as recited in claim 60, wherein each of said at least one primarybase station and said pair of secondary base stations coupled thereoflistening for tag signals within said tag detecting cell following saidat least one of said at least one primary base station and each of saidpair of secondary base stations sending query signal to said at leastone tag within said detecting cell.
 63. A method as recited in claim 62,further comprising each of said at least one tag responding sequentiallyto said query signals.
 64. A method as recited in claim 60, wherein eachof said pair of secondary base stations communicating their respectivereceived signal to said at least one primary base station coupledthereto; said at least one primary base station determining the locationof said at least one tag within said tag detecting cell.
 65. A method asrecited in claim 60, further comprising transmitting to a central servercoupled to said at least one primary base station said location of saidat least one tag.
 66. A method as recited in claim 65, wherein saidcentral server using said location of said at least one tag to performtag grouping.
 67. A method as recited in claim 60, wherein saidactivating at least one tag includes communicating to a central server alist of activated tags.
 68. A method as recited in claim 67, whereinsaid at least one primary base station communicating with said centralserver to obtain said list of activated tags.
 69. A method as recited inclaim 68, wherein said at least one primary base station transmittingsaid list of activated tags to each secondary base station of said pairof secondary base stations.
 70. A method as recited in claim 68, whereinsaid activating at least one tag includes transmitting to said at leastone primary base station a list of checkpoints including a sequence ofpositions along an expected itinerary of said at least one tag.
 71. Amethod as recited in claim 70, wherein said at least one tag verifyingthe concordance of said checkpoints along its actual itinerary andsending an alarm if any difference is detected between said checkpointsand predetermined positions along said itinerary.
 72. A method asrecited in claim 70, wherein said at least one primary base stationcommunicating a lost of said at least one tag to said central serverwhen a tag signal broadcasted by said at least one tag is not receivedat a predetermined time by said at least one primary base station or byone of said pair of secondary base station while said list ofcheckpoints includes a position in the detecting cell including saidprimary base station corresponding to said predetermined time.
 73. Amethod as recited in claim 72, further comprising at least one of saidat least one primary base stations and each of said pair of secondarybase station requesting an emergency identification of said at least onetag following said communicating a lost of said at least one tag.
 74. Amethod as recited in claim 72, further comprising said primary basestation estimating a probable position of said at least one tagfollowing said communicating the lost of said at least one tag.
 75. Amethod as recited in claim 72, further comprising said primary basestation transmitting at least one query signal to communicate with saidat least one tag following said communicating the lost of said at leastone tag.
 76. A method as recited in claim 60, wherein listening for tagsignals within said tag detecting cell includes said primary basestation querying tags within said detecting cell.
 77. A method asrecited in claim 76, wherein said primary base station querying tagswithin said detecting cell following receiving a request from a centralserver to which said primary base station is coupled.
 78. A method asrecited in claim 60, wherein said activating at least one tag includessaid at least one tag receiving an identification code.
 79. A method asrecited in claim 60, wherein said activating at least one tag includestransmitting to a central server coupled to said at least one primarybase station at least one of said information pertaining to said objectto be tracked and said identification code.
 80. A method as recited inclaim 60, wherein said activating at least one tag includes firstreceiving said information pertaining to said object to be tracked. 81.A method as recited in claim 60, wherein said tag signal indicative ofinformation pertaining to said object to be tracked being broadcast atpredetermined interval.
 82. A method as recited in claim 60, whereinsaid activating at least one tag includes verifying the integrity ofsignal transmission from said at least one tag.
 83. A method as recitedin claim 60, wherein using said three received signals to determine thelocation of said at least one tag within said tag detecting cell isachieved using at least one of Time Difference Of Arrival (TDOA),Received Signal Strength (RSS) and Artificial Neural Network (ANN)techniques.
 84. A method as recited in claim 60, wherein said at leastone tag comprising a plurality of tags; the method further comprisinglogically grouping said plurality of tags according to one of saidobject-related information and said tag-related information, yielding atleast one tag bundle.
 85. A method as recited in claim 84, wherein saidlogically grouping is performed dynamically.
 86. A method as recited inclaim 84, further comprising monitoring said at least one tag bundle.87. A wide area intelligent object tracking system comprising: aplurality of tags, each to be attached to a different object to betracked; each of said plurality of tags including a memory to receiveobject-related information pertaining to said different object to betracked and being configured so as to generate and transmit a tag signalindicative of said object-related information; a plurality of primarybase stations, each coupled to a pair of secondary base stations so asto define a tag detecting cell; said plurality of primary base stationsdefining overlapping cells; each of said primary and two secondary basestations being configured to receive said tag signals, yielding threereceived signals to be processed by said primary base station yieldingthe location of said tag within said cell; and a central server coupledto said plurality of primary base stations for receiving at least one ofsaid tag signals and said location of said tag within said cell andincluding an expert agent for tracking said plurality of tags withinsaid overlapping cells.